stale-while-revalidate is an HTTP attribute on the Cache-Control header that defines an extra window of time during which a cache (proxy, user agents) can use a stale asset as long as it revalidates it asynchronously. This improves subsequent page load latencies as stale assets are non longer in the critical path.


Established standard

Status in Chromium


Origin trial (tracking bug) in:

  • Chrome for desktop release 69
  • Chrome for Android release 69
  • Android WebView release 69

Consensus & Standardization

After a feature ships in Chrome, the values listed here are not guaranteed to be up to date.

  • No public signals
  • Mixed public signals
  • No public signals
  • Positive


Last updated on 2018-12-10